N‑(6‑Aminohexyl)‑5‑chloro‑1‑naphthalenesulfonamide (W-7), a kind of adjuvant chemotherapy, can bind to calmodulin and inhibit Ca2+ /calmodulin-regulated enzyme activities and cell proliferation. Similar to calmodulin, euplotes octocarinatus centrin (EoCen) belongs to EF-hand superfamily of calcium-binding proteins. It is associated with nucleotide excision repair (NER), cell division cycle and ciliogenesis. In the present study, the comparative interaction of W-7 with EoCen was first examined by using various spectroscopic, calorimetric methods and molecular docking...

We synthesized five iron chelator derived from 2,6-diacetylpyridine bis(acylhydrazones) and proved their iron complexes structure by X-ray single crystal diffraction. These ligands have a significant anticancer proliferative activity and low cytotoxicity against normal cells. The Fe(III) complexes show reduced cytotoxic activity compared to the metal-free ligands. Anticancer mechanism studies indicate that ligands with a potential anticancer proliferation activity by inhibiting the activity of ribonucleotide reductase...

Peroxide reduction involving Fe(II) (i.e., Fenton chemistry) forms hydroxyl radicals which cause oxidative damage to DNA in vivo. Sulfur and selenium compounds have been investigated for their antioxidant properties in preventing this metal-mediated oxidative damage. The effect of the coordination of sulfur/selenium derivatives of imidazolidinone (thiones/selones) on the electronic structure and reduction potential of Fe(II) ions solvated or coordinated to guanine are examined using density functional theory (DFT)...

Escherichia coli ZraP (zinc resistance associated protein) is the major Zn containing soluble protein under Zn stress conditions. ZraP is the accessory protein of a bacterial two-component, Zn2+ sensitive signal transduction system ZraSR. ZraP has also been reported to act as a Zn2+ dependent molecular chaperone. An explanation why ZraP is the major Zn protein under the stress condition of Zn2+ overload (0.2 mM) has remained elusive. We have recombinantly produced E. coli ZraP and measured Zn2+ and Cu2+ affinity in-vitro using Isothermal Titration Calorimetry...

Copper coordinated with amino acid residues is essential for the function of many proteins. In addition, copper complexed to free l-Histidine, as [Cu(His)2 ], is used in the treatment of the neurodegenerative Menkes disease and of cardioencephalomyopathy. This study was aimed to coordinate copper(II) with four small ligands (l-Serine, l-Histidine, Urea and Biuret) and to evaluate structural features, stability, antioxidant activity and neuronal compatibility of the resulting complexes. All complexes were synthesized with CuCl2 and purified by precipitation in alcohol...

Cadmium (Cd) is a ubiquitously distributed environmental pollutant that is highly toxic to liver. Trehalose (Tr), a novel autophagy activator, has been shown to exert cytoprotective effect in numerous pathological processes. However, it is yet to be established whether Tr affords protection against Cd-induced hepatotoxicity. Here, we aimed to investigate the protective effect of Tr on Cd-induced hepatic injury in rats. First, Cd-elevated serum hepatic enzymes and liver pathological changes were significantly ameliorated by Tr treatment...

Eight half-sandwich iridiumIII (IrIII ) complexes of the general formula [(η5 -Cpxbiph )Ir(O^N)Cl] (Cpxbiph is tetramethyl(biphenyl)cyclopentadienyl, and the O^N is α-picolinic acid chelating ligand and its derivatives) were synthesized and characterized. Compared with cis-platin widely used in clinic, target IrIII complexes showed at most five times more potent antitumor activity against A549 cells by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. IrIII complexes could be transported by serum albumin, bind with DNA, catalyze the oxidation of nicotinamide-adenine dinucleotid (NADH) and induce the production of reactive oxygen species, which confirmed the antitumor mechanism of oxidation...

The synthesis and characterization of {Ln[12-MCGa III N(eshi) -4]}2 (iph)4 and {Ln[12-MCGa III N(shi) -4]}2 (miph)4 metallacrowns (MCs), where shi3- is salicylhydroximate, eshi3- is 4-ethynylsalicylhydroximate, iph2- is isopthalate, and miph2- is 5-maleimidoisophthalate, is reported. The ethynyl functionality allows for coupling of MCs to azides using copper(I) catalyzed alkyne-azide cycloaddition (CuAAC), while the maleimido functionality allows for coupling of the MCs to thiol-bearing compounds. We demonstrate these coupling reactions using benzyl azide for the former and cysteamine for the latter, with complete conversion shown by ESI-MS...

We synthesized and characterized 15 new derivatives of the highly anticancer-active platinum(II) complex [{cis-Pt(NH3 )2 }2 (μ-OH)(μ-tetrazolato-N2,N3)]2+ (5-H-Y) by making substitutions at tetrazole C5. We then evaluated the comprehensive structure-cytotoxicity relationships of a total of 23 derivatives in two murine lymphocytic leukaemia cell lines, sensitive and resistant to cisplatin. We also report the in vivo antitumor efficacy of three ester derivatives, two of which exhibited much higher efficacy than oxaliplatin against mouse homografted Colon-26 colorectal tumor...

The complexation of Cm(III) with human serum albumin (HSA) was investigated using time-resolved laser fluorescence spectroscopy (TRLFS). The Cm(III) HSA species is dominating the speciation between pH 7.0 and 9.3. The first coordination sphere is composed by three to four H2 O molecules and five to six coordinating ligands from the protein. For the complex formation at pH 8.0 a conditional stability constant of logK = 6.16 ± 0.50 was determined. Furthermore, information on the Cm(III) HSA binding site were obtained...

Several toxic effects arise from aluminum's presence in living systems, one of these effects is to alter the natural role of enzymes and non-enzyme proteins. Aluminum promotes the hyperphosphorylation of normal proteins. In order to assess the aluminum-binding abilities of phosphorylated proteins and peptides, the interaction of aluminum at different pH with serine and phosphoserine is studied by a Density Functional Theory study, combined with polarizable continuum models to account for bulk solvent effects, and the electronic structure of selected complexes are analyzed by Quantum Theory of "Atoms in Molecules"...

In this work, we present the development of a high water soluble biological nanoprobe through the covalent bonding of β-CD onto the surface of iron oxide‑gold nanoclusters (Fe3 O4 @Au@β-CD). Fe3 O4 @Au@SiO2 NPs were also prepared for comparison. The maximum emission peak of magnetic fluorescent NPs red-shifted by 30 nm and the lifetime was also elongated to 5.21 μs after surface modified with β-CD. The relaxivities and in vitro magnetic resonance imaging ability of the resultant magnetic fluorescent NPs were also studied, indicating that Fe3 O4 @Au@β-CD NPs have the lowest r2 /r1 ratio and could be a potential T2 contrast agent for MR imaging...

Herein we present examples of the application of the 13 C-13 C Nuclear Overhauser Effect Spectroscopy (NOESY) experiment to the study of metalloproteins and we critically discuss the advantages and drawbacks of the method as a function of the molecular size of the investigated systems. The contribution is focused on a few case studies among the systems analyzed in the group of the corresponding author. The 13 C-13 C NOESY experiment represents the gold standard for the observation of NMR signals in the 480 kDa ferritin nanocage and for monitoring its interaction with iron...

The cationic Ga(III) and Zn(II) phthalocyanines carrying N-methyl-pyridinium groups at eight peripheral β-positionshave been synthesized. These complexes are highly soluble in dimethyl sulfoxide (DMSO) and moderately soluble in water and phosphate buffered saline (PBS); both Ga(III)Cl and Zn(II) complexes have shown no aggregation in water up to 1.2 × 10-4 and 1.5 × 10-5 M, respectively. A higher water-solubility of Ga(III)Cl complex as compared to Zn(II) complex is ascribed to the presence of an axially coordinated chloride...

Alzheimer's disease (AD) is one of the most common age-related neurodegenerative disorders. Aggregation of amyloid-β peptide into extracellular plaques with incorporation of metal ions, such as Cu2+ , and reduction of the neurotransmitter acetylcholine levels are among the factors associated to the AD brain. Hence, a series of 7-chloro-4-aminoquinoline Schiff bases (HLa-e) were synthesized and their cytotoxicity and anti-cholinesterase activity, assessed for Alzheimer's disease. The intrinsic relationship between Cu2+ and the amyloidogenic plaques encouraged us to investigate the chelating ability of HLa-e...

Six gallium(III) complexes (Ga1-Ga6) with 2‑quinolinecarboxaldehyde thiosemicarbazone analogues were synthesized and characterized. These gallium(III) complexes exhibited potent anticancer activity and exceeded that of the corresponding metal free ligands. Importantly, these gallium(III) complexes have a strong selectivity for tumor cells. Through the study of cellular mechanisms, we have found that the lipophilicity of ligands is closely linked to the antitumor activity of gallium(III) complexes. Additionally, we have chosen Ga6 with the best anti-tumor activity to study the mechanism of apoptosis...

In this work, we designed polysaccharide-metal complex of dopamine-modified pectin linking ruthenium compound, which exhibited a certain inhibition specificity to human renal cell adenocarcinoma cell line 786-O. The chemical structure and physical properties of the polysaccharide-metal complex were well characterized by multiple analysis methods. The multi-spectral results revealed that pectin-dopamine have been successfully coordinated by ruthenium complex to form nano-conjugates, which self-assembled into relatively regular nanospheres of approximately 200 nm...